The present invention relates to a mechanism for divan beds enabling the adjustment of a divan bed into three positions, xe2x80x9cbedxe2x80x9d, xe2x80x9cdivanxe2x80x9d and xe2x80x9crelaxxe2x80x9d.
In the state of the art concerning the above mentioned applications, there are already mechanisms enabling the adjustment into three positions of a divan bed. Such mechanisms, as the ones described in the European patents 0 380 156 and 0 807 390, are generally release mechanisms comprising two reciprocally moving angle bars, a kinematics similar to that of an articulated quadrilateral, some elements forming a seat and a pawl to lock the divan bed in the xe2x80x9cdivanxe2x80x9d and xe2x80x9crelaxxe2x80x9d positions, and at least two toothed profiles that, engaging with each other, determine the reciprocal position of the angle-bars and, also, the position of the frames supporting the divan bed.
The known applications, however, are characterized by many constructive disadvantages. The described kinematic system is very complicated by the high number of components and hinges; the toothed profiles do not work properly because they are tangentially stressed and not axially stressed.
The invention is different from the devices on the market thanks to the fact that the same angle-bars (joining the frames of the divan bed) are the elements of a release mechanism which enables the three positions to be obtained, but which is stable respect to the divan bed base, while the articulated quadrilateral stiffly moves the angle-bars into the other three positions.
The main feature of the mechanism is the unequivocal positioning between the angle-bars and the quadrilateral elements, without any other additional element as, for example, stop elements, like a ratchet or pawl.
Another object of the invention is a substantial reduction of the number of the hinges, to a number that does not exceed five, as will be seen from the detailed description.